The present invention relates to a treatment process which makes it possible to modify the chemical structure of securities, bank notes or paper documents during their transportation or their storage, either in a vehicle or by a man on foot, thus making it impossible for criminals to be able to reuse them.
According to the invention, a chemical treatment process is provided which makes it possible to modify the chemical structure of securities, bank notes or paper documents during their transportation or their storage, either in a vehicle or by a man on foot, thus making it impossible for criminals to be able to reuse them.
According to other characteristics:
the physicochemical process is a polymerization or a crosslinking of the cellulose molecules of which the securities, bank notes or paper documents are composed, by dispersion of a chemical over the latter;
the product which makes possible the polymerization or the crosslinking of the cellulose molecules is a chemical of one of the following types:
carboxylic acids, to form esters (RCOOH),
alkanoyl halides, for esters (RCOX, where X is a halogen),
sulphonic acids, for sulphonic esters (RSO2OH),
isocyanates, for urethanes or carbamates (RNCO),
phosgene, for carbonates.
Bank notes, or paper securities, and the like, are manufactured with paper prepared from cellulose. The principle which makes it possible to render these notes, securities or documents unusable is that of structurally modifying the existing molecules composing the structure of the bank notes or securities. This modification of the basic cellulose molecule is known as polymerization or crosslinking of the cellulose fibrils with one another.
The chemical formula of cellulose is as follows: 
This formula reveals hydroxyl functional groups (xe2x80x94OH) capable of reacting with other chemical molecules. This is because alcohol, or hydroxyl, groups can react covalently with:
carboxylic acids, to form esters (RCOOH),
alkanoyl halides, for esters (RCOX, where X is a halogen),
sulphonic acids, for sulphonic esters (RSO2OH),
isocyanates, for urethanes or carbamates (RNCO),
phosgene, for carbonates.
In order to provide for crosslinking in two or three dimensions, each type of product must exhibit at least two groups. These products are represented diagrammatically in the following way: 
To avoid an intramolecular reaction of the same paper fibril, trifunctional substances will be favoured.